Mineralization of bisphenol A by advanced oxidation processes

BACKGROUND: Endocrine disruptors, as in the case of bisphenol A (BPA), are,increasingly found in aqueous effluents. The degree of mineralization of a bisphenol A (BPA) aqueous solution after applying several oxidation treatments has been investigated. RESULTS: UV-C photolysis of BPA allowed calculation of the quantum yield, phi(lambda=254) = 0.045 +/- 0.005 mol Einstein(-1) but only 15% of the initial organic carbon content (TOC) was eliminated. Better results (80% conversion) were obtained after TiO2 addition. Ozone inmediately reacts with BPA. Again, TiO2 addition in the presence-of 03 was capable of increasing the mineralization level (60%). The photolytic ozonation of BPA was capable of completely eliminating TOC. The presence of activated carbon in the O-3/UV and O-3/UV/TiO2 systems significantly enhanced the TOC removal reaction rate (100% conversion in 20 min). CONCLUSIONS: Processes such as ozonation or photolysis are capable of efficiently removing BPA from water however, mineralization levels are rather low. Addition of TiO2 to O-3 or UV-C significantly enhances TOC removal. The remaining organics still account for an average 20-40% of the initial organic carbon. The combination Of O-3/UV-C is capable of completely mineralizing BPA. Activated carbon and/or TiO2 addition to the system O-3/UV-C improves the TOC depletion rate. (c) 2008 Society of Chemical Industry